Surface runoff and pollutant load response to urbanization, climate variability, and low impact developments – a case study

Abstract

Using the Storm Water Management Model (SWMM), this study evaluated the impacts of (a) 20% and 50% urbanization at the mountainous Mahabad Dam watershed in Iran, as probable future land developments, (b) the urbanization location (near the outlet, in the middle, and at the far end of the watershed), (c) climate variability (increase in evaporation and rainfall intensity), and (d) implementing vegetative swales as low impact developments (LIDs), on watershed-generated runoff and pollutant loads (total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP)). Combination of the above-mentioned factors resulted in 17 scenarios, and each scenario was run for a 12-hour simulation in the model. The results indicated that based on land developments, areas with more dominant agricultural land generated more TN and TP, areas with more undeveloped lands generated more TSS, and more urbanized areas generated more runoff. Moreover, the 50% urbanization scenario resulted in more runoff and pollutant loads, compared with the 20% urbanization scenario. Under scenarios with climate variability, runoff and pollutant load peaks occurred earlier in time, due to the higher intensity rainfall events. Furthermore, LIDs decreased pollutant loads up to 25%, indicating their effectiveness in decreasing the impact of urbanization on receiving water bodies.

Relationship between Sunspot Numbers and Mean Annual Precipitation: Application of Cross-Wavelet Transform—A Case Study

“…Jamali et al showed that lack of adaptation to climate variations leads to a considerable decrease in efficiency in Iran's Karkheh Hydropower in the future [51]. Some examples of a lack of insufficient climate assessment studies and improper managements in Iran are: damages caused by heavy rains; floods and damages on many houses, infrastructure, water and power supply; groundwater depletion; droughts and their impacts on food quality and quantity, economy, health, and people's livelihood; drying lakes; sand storms; and ecosystem degradation [52][53][54][55][56][57][58][59][60][61][62]. These issues indicate the necessity of implementing sustainable adaptation and mitigation plans, considering possible variations in climate.…”

Spatial Variation Pattern Analysis of Hydrologic Processes and Water Quality in Three Gorges Reservoir Area

“…Land use is identified as a vital factor affecting the runoff generation, soil erosion and nitrogen and phosphorus loads in a watershed [21,45]. Forests have a great ability to intercept precipitation and increase infiltration, because of their mature canopy, rich litter humus layer and complex root system [46].…”

Operational and technical performance of a water distribution network in Oman

“…The computational predictions are based on mathematical modelling. The mathematical models can be of assistance in obtaining a reasonably accurate representation of the water quality across the system, which can later be verified or confirmed through limited sampling (Jalal 2008;Nazari-Sharabian et al 2019a, 2019b. The hydraulic models mainly consider advection and decay while calculating the water quality in the water distribution system.…”